docs: def render_scene(self):
          "render scene one time"
          self.init_gl() # should be a no-op after the first frame is rendered
          glfw.make_context_current(self.window)
          self.renderer.render_scene()
          # Done rendering
          # glfw.swap_buffers(self.window) # avoid double buffering to avoid stalling
          glFlush() # single buffering
          glfw.poll_events()